1. Field of the Invention
This invention relates to grinder apparatus, and more particularly, to grinder apparatus useable for grinding grains, such as wheat, from the grain to relatively fine flour using a cooperating burr and a helical cutter and a mating pair of conical grinding stones which receive the cracked grain from the burr and helical cutter.
2. Description of the Prior Art
Grinder apparatus of the prior art typically use a pair of generally flat grinding stones or wheels for grinding wheat, and other grains. Such grinding stones or millstones have been used far back into antiquity. While the general design of the grinding stones has not changed, the overall size of the grinding apparatus has decreased substantially. Thus there are now home grinders using the generally parallel grinding stones which are relatively compact, and yet for home use they are rather cumbersome and large, as compared to other household appliances.
Many different forms of power have been applied to turn grinding stones. Or, more nearly correct, to turn one of a pair of grinding stones. The other of the pair of stones generally remains stationary. Beasts of burden have been used to turn grinding stones, and water power, such as water wheels, have also been used to turn the stones. In recent decades, electric motors have been used to turn grinding stones.
It is highly desirable to turn the stones at a relatively slow surface speed so as to produce a minimum of heat. With a motor speed of between about 1000 and 1750 rpm, the way to reduce the surface speed is to minimize the diameter of the grinding stones. Most of the grinders of the prior art have used flat stones, in which the diameter is maximized, thus producing relatively high surface speeds.
Heat is generated by the friction of the material to be ground, or being ground, as one of the grinding wheels or stones moves or rotates with respect to the other one. The desirability of maintaining a relatively low grinding surface speed so as to avoid excessive heat is for two reasons. The first reason is to avoid burning or scorching the material being ground. The second reason is of more recent discovery, and that is simply to avoid a destruction of the food value or nutrients in the material being ground. It may be expressed that the two primary reasons for avoiding heat are substantially interrelated. That is, if heat is sufficient to scorch or burn the flour or other material being ground, there will be an accompanying destruction of some of the food value in the material.
With respect to home use, the popularity of home grinders is increasing. The idea behind home grinders may be attributed to the concepts of freshness, increased food value, and convenience. By purchasing wheat, rice, or other grains in bulk, a householder has the convenience of making bread or other grain products at his convenience. When one grinds his own wheat, the product is certainly fresher than a product which is commercially made. Moreover, there may be a substantial saving in cost in purchasing the raw grains, converting the grain to flour, and then making the end product for home consumption. There are some nutritionists who claim that a substantial amount of the food value present in the whole grain is lost in the grinding and manufacturing or baking process, as commercially exploited. Those same nutritionists feel that the same food value is not lost, but rather is retained in the product home-made from home-ground grain products. Accordingly, recent years have seen a resurgence of home grinding apparatus for the typical home owner.
Such home grinding apparatus is, as pointed out above, generally larger than is desirable in the contemporary kitchen. Due to the generally "large" diameter of the grinding stones, which is typically about 8 inches, the housing for the grinding apparatus tends to be larger than most householders desire. The apparatus of the present invention does not utilize a pair of flat grinding wheels, but rather uses a pair of generally mating conical grinding wheels which provide for a much more compact grinding apparatus than is found in the prior art. Moreover, the apparatus described herein, because of the design of the cutters and the grinding wheels, is able to use smaller quantities of energy, as expressed in the terms of a small electric motor, and thus there is a substantial savings in both cost and in energy in the utilization of the present apparatus.